Fewer than 4 percent of known alien solar systems are likely to have an asteroid belt like the one in our own neck of the woods, researchers found. Belts that look like ours may help spur the evolution of life, seeding rocky planets with water and complex chemicals but not pummeling the worlds with a constant barrage of violent impacts.

"Our study shows that only a tiny fraction of planetary systems observed to date seem to have giant planets in the right location to produce an asteroid belt of the appropriate size, offering the potential for life on a nearby rocky planet," study lead author Rebecca Martin, of the University of Colorado in Boulder, said in a statement. "Our study suggests that our solar system may be rather special."

"To have such ideal conditions you need a giant planet like Jupiter that is just outside the asteroid belt [and] that migrated a little bit, but not through the belt," said study co-author Mario Livio of the Space Telescope Science Institute in Baltimore.

"If a large planet like Jupiter migrates through the belt, it would scatter the material," Livio added. "If, on the other hand, a large planet did not migrate at all, that, too, is not good because the asteroid belt would be too massive. There would be so much bombardment from asteroids that life may never evolve."

"The Hubble Deep Field (HDF) is an image of a small region in the constellation Ursa Major, constructed from a series of observations by the Hubble Space Telescope. It covers an area 2.5 arcminutes across, about one 24-millionth of the whole sky."

Those aren't stars. Those are galaxies. And there are 24 million times more of the ones we can see, not to mention the ones we can't.

For all practical purposes, the universe is infinite. There are probably an infinite number of life-supporting planets out there, but for all practical purposes each of them is an infinite distance away.

We will not be making contact with ET anytime soon.

2
posted on 11/03/2012 10:50:04 AM PDT
by E. Pluribus Unum
(Government is the religion of the psychopath.)

Even a tiny fraction of the planets in this galaxy is a gigantic number. Saying that the conditions for life can not be duplicated is pure speculation. I think that life must exist other places in the universe because There is never only one of any KIND of thing. By the nature of the Universe there must be other life bearing planets. For There to be only one in this unimaginably large universe would be like there only being one raindrop, tree, solar system or grain of sand. Try to think of any fundamental concept such as planet, cloud, rainbow or ice crystal with only one concrete example. Of course Earth is the only example of “life bearing planet” that we know of now but we have not been to any other solar systems yet to check and I suspect, again based on my observation of the nature of the universe, that when we do venture out to the stars we will find life is as common as raindrops here on earth.

I am not going to read the book. I don’t have time. I did read a synopsis and I see nothing about the book that states that life is only on the Earth. They claim that the conditions for life are exceedingly rare. I am sure they have some theories about that. But we have barely begun to even find extra solar planets let alone map any other solar systems. We are as a matter of fact finding many more planets than scientists expected and planets around binary and trinary systems where many scientists thought we wouldn’t. I am not going to eat crow because of one book by two scientists. They could be wrong and so could I. I was simply saying that if Earth is the only planet with life or one of only a tiny handful in the vastness of the universe it would go against the order of the universe as I have observed it.

I think that any planet that has liquid H2O for 100s of millions of years is very likely to have life.

The catch - The circumstances where liquid H2O can exist for time frames like that are complex and infrequent. It takes more than just the right distance from the right sized star. Having heavier elements around, such as oxygen has a whole set of conditions.

13
posted on 11/03/2012 4:47:24 PM PDT
by Triple
(Socialism denies people the right to the fruits of their labor, and is as abhorrent as slavery)

I am not a scientist if that’s what you mean. I definitely can’t do the math. But, I have a pretty good brain and I can think conceptually. I was speaking philosophically. I can observe existence and form concepts about it without having a Phd. One of the authors is an astrophysicist. There are other astrophysicists who believe as I do. The other is a philosopher. That doesn’t mean I should believe everything he says. There are many philosophers who many different ideas. They can’t all be right.

I note that you have not addressed my philosophical argument about there never being only one of any kind of thing. I have tried to come up with an example and I can’t. If you can I would be very interested to hear it.

Why is it so important to you that the Earth be the only life bearing planet?

As to facts there really aren’t that many known about solar systems other than our own. That’s a pretty small sample. Scientists can come up with a lot of theories but we really have only begun to test them and as I already said they were surprised that they found so many extra solar planets so fast and around binary stars as well. It’s kind of like the deep sea vents and all the strange life that lives down there. Scientists were surprised to find them. There were probably a lot of scientists who were sure it would be barren down there. As far as life on other planets we will probably have good evidence for it in the next 10 years by spectroscopic analysis of the light shining through atmosphere’s.

Many extrasolar planets have been catalogued in this present day; the problem is, no earth-like planets have been seen — and by that I mean the right size and at a distance from its star to not be fried nor frozen solid. Most discovered extrasolar planets have been Jupiter-sized or larger.

I doubt that you or anyone could maintain over the long run that there is never just one kind of thing. It could very well be, that the existence of the right kind of star and a planet of just the right size and right orbit, when combined with the probability of the start of life (not to mention development of sentient beings) that the odds end up greater than there are seconds left in the Universe....

That’s true. Many of them are much larger than Earth and most of them so far have been very close in to their stars. They have found some that are close to Earth sized though and some of those are in their star’s so called habitable zone. The one around Gliese 581g is an example. I just think that it is way too soon for scientists to say that the conditions of life are so exceedingly rare that they won’t be duplicated. We have found, what, 1500 or so so far and the reason most of those are giant planets is that they have a much greater pull on their star and are easier to detect. It’s much harder to detect Earth sized planets. And What about gas giants with Earth sized moons in the habitable zone?

Another thing is that life seems to be really really tough. There are virtually no places on earth where we don’t find some kind of life from the hottest hot springs to the coldest ocean depths and even down miles into the crust.

I asked you why it was important to you that the Earth was one of a kind. I’ll tell you my reason that it is important to me that it isn’t one of a kind. It is that it would seem to me to be a contradiction of the order of the universe and I don’t like contradictions in my metaphysics.

The book you mentioned does sound like something I would be interested in reading and I will see if I can get an audio copy since I listen to a lot of books while I am working. But since you have read it does it have an answer to my philosophical question. Can you give me an example of a concept with only one concrete? I am not being flippant with you, I would really like to know if there is one because I have racked my brain trying to falsify my idea of there being multiples of everything. Since that is what I base my theory of life on other planets on I would really like to hear your thought on that. If we can form a concept of “life bearing planet” doesn’t that mean there must be other examples out there? And since processes are certain and universal and that life can exist in many extreme environments, doesn’t it seem likely that it is common out there?

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